# CVE-2026-4270

## Summary

- **CVE ID:** CVE-2026-4270
- **Severity:** MEDIUM
- **CVSS Score:** 6.8 (CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-424
- **Published:** Mar 16, 2026
- **Last Modified:** Mar 16, 2026

## Description

Improper Protection of Alternate Path exists in the no-access and workdir feature of the AWS API MCP Server versions >= 0.2.14 and < 1.3.9 on all platforms may allow the bypass of intended file access restriction and expose arbitrary local file contents in the MCP client application context.

To remediate this issue, users should upgrade to version 1.3.9.

## Affected Products

- AWS — AWS API MCP Server (0.2.14)

## References

- [CNA](https://aws.amazon.com/security/security-bulletins/2026-007-AWS/)
- [CNA](https://pypi.org/project/awslabs.aws-api-mcp-server/1.3.9/)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.13%
- **EPSS Percentile:** 3.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._